Total absolute nonsense. First of all, intelligence is useful in numerous things in life, not just in war. Second of all, even amongst animals there is war - war between species and war between those in the same species for mates. So intelligence is useful in numerous situations as anyone with half a brain should understand.
That's a straw man argument. I didn't say intelligence is only useful for war, only that war is the evolutionary reason we are intelligent. Those of us alive today are the living offspring of the winning warmakers. You attack me in a warlike anger because you are the product of war. It's both our nature, and we are naturally very good at it.
We are about to go to war with Iraq. They will lose because they are not as advanced at war as you and I. This is human evolution in action. We aren't going to kill all the Iraqis, but if they tick us off enough, at the press of a few buttons we can turn Iraq into a radioactive sheet of glass. Recent history shows it's not totally beyond us to do that.
This debate was hashed out in 1882. If you would like a better explanation you can read it in Darwin's own words at http://pages.britishlibrary.net/charles.darwin/texts/descent/descent05.html